What RS232 baud rate do you use - excluding HAAS?

[gar]

051211-1712 EST USA

Poll of -- What RS232 Baud Rate do you use?

I have selected multiple choice so you should be able check each baud rate that you use.

This poll is essentially the same as the one under HAAS machines. The intent here is that this poll should apply to non-HAAS machines.

With a broader machine community I expect some difference in the shape of the distribution curve.

Comments on why you use a given baud rate, your cable length, and communication parameters would be useful. An example of why might be --- the machine vendor said to use ---- .

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[Chris D]

The curiosity is killing me. First there was a post about baud rate for Haas, now for "all other machines". Then there was a post about what features DNC should have.

I am guessing you are trying to write a DNC application?

Chris

[gar]

051216-1212 EST USA

Chris D:

We have two products useful for RS232 communication.

By asking questions about what users are doing, their equipment limitations, their problems, and trying to get some of the whys, we can better direct our discussion of our equipment.

Some of the discussion on our web site is of general use. www.beta-a2.com or www.beta-aa.com . The -aa site has little to do with CNC.

We made two mistakes on our HAAS poll. First, I think we discouraged some users from reponding by not making the poll private. From a poll stand point I do not care who answers what so long as it is honest. So this poll is private unless one chooses to provide a response. Second, I did not allow for multiple choices. There may be many shops that operate at multiple baud rates (ours being one because we have old and new HAAS machines), and this information was excluded from the results.

Since newer, by 98, HAAS machines have a 115.2 kbaud maximum capability, and previously 38.2 kbaud, and most other machines top out at 9600 baud to 19.2 kbaud the HAAS poll was put under HAAS because that sort of automatically eliminated other machines.

From talking to service and sales people we got the qualitative response that 9600 baud was most common. So far the polls seem to indicate this.

This poll, hopefully excluding HAAS, is showing a surprising number of responses at 115.2 kbaud.

Different users have different types of RS232 problems. The dominate problem is how to wire one RS232 to another. This I conclude from the large number of Google hits we get with questions relating to wiring.

To try to see what users consider to be their problems is the reason for the poll with no categories and the requirement for a written response. So far no responses.

We know some users operate at 9600 baud simply because the salesman told them to use it. Others operate at 2400 or 4800 because of handshake or noise problems. Some are drip feeding, running at a lower baud rate than the CNC max capability, and their machine runs in jerks because of starvation. Many do not want to solve their problem. Others have total inability to communicate with RS232 because of noise. Then some have had their equipment or parts damaged because of ground problems.

Broadly speaking there is overall a great lack of understanding about RS232 and serial communication, grounding, and noise.

Only those that have had thousands of dollars of damaged equipment care about isolation. Sort of after the fact.

Biggest interest is high baud rates, long cable, and large files.

Excluding the 115.2 kbaud catergory the HAAS poll is a fairly good normal distribution, visual guess. This poll so far is tending to be a flatter distribution.

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[swarfmacdaddy]

How do i determine my baud rate? Please forgive my ignorance.

[gar]

060101-2201 EST USA

swarfmacdaddy:

Most useage of RS232 is for asynchronous serial communication of data.

In a serial communication system parallel data bits are sent one by one over a two wire connection and reasembled into the parallel word at the destination. If this was not done you would need a separate wire for each of the parallel bits and a common reference wire. Serial communications is simpler and cheaper for long communication paths. The old Morse code was a type of asynchronous serial communication.

Asynchronous means that there is no separate clock signal sent from source to destination to define when a data bit should be read, and there must be a means to synchronize each data word.

To provide a clock to time the points in a serial word to read the individual bits it is necessary to have an accurate clock generator at each end of the communication path. This is the baud rate generator. For an 8 bit data word the accuracy of the clocks at both ends should be better than a few percent.

Typical baud rates are 110, 150, 300, 600, 1200, 2400, 4800, 9600, 19.2k, 38.4k, and 115.2k . If the baud rate clocks are not the same at both ends you will get scrambled data. Baud rate is in bits per second. The higher the baud rate the faster you can transfer data. The 110 rate derived from the old Teletype days and was defined by the maximum practical mechanical speed of the machines.

Besides baud rate there are other parameters that must be set identical at both ends of the communication channel.

In your CNC machine there will be some place (relatively permanent memory locations) where these parameters are stored. In a HAAS machine it is very easy to find the parameters and you can determine what they are without a manual. Other CNC machines will encode the parameters in a fashion that will almost certainly require you to use and understand the CNC manual. Fanuc falls in this category.

At the computer end if you are using Windows, then your communication program will have something like Setup and this is probably where the serial communication parameters are located. Then your program when executed forces Windows to the required parameter values. The various serial communication parameters are Baud Rate, Data Bits, Stop Bits, Parity (includes none which does not use a bit), and Handshake. As said above all of these much match at both ends.

This does not provide a very good answer on how to find your baud rate.

But if you have a HAAS, then it is easy -- you either seach for the setting, it is about the fourth page in settings, or get the setting numbers from the manual. In Fanuc you will have a hard time, but go to the manual and see if you can understand their discussion.

At the computer end the instructions for the program may help, but these are usually not very good these days. Thus, you may have to search thru different paths to find where these parameters are entered and displayed. In HyperTerminal for XPPro you pick an entry under NAME, then Files, Properties, Connect To, Configure -- here you find baud rate. This is rather unobvious and bad design to go thru so many steps. I would suggest that once I picked Name that selecting Tools would give me Settings where all would be displayed at one level. Maybe even right clicking the name would directly take me to all the settings on one page.

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[swarfmacdaddy]

Gar,
I get it now. I ask cuz i was wondering how this relates to someone as myself using geckos and a retro fitted chinese mill at home. Could this have anything to do with the following message i get when i boot into turbocnc v.4 ."Long interrupt latency detected, turbo cnc will problably not run well. mean timer latency is 5.51 micro seconds max is 289.00 min is 5.00 ,frequency where jitter approaches 10% is 21637.5. Also when i am cutting a part from file it works fine, but when i try jogging the machine it pauses for a second or two sporadically.Which really pisses me off when im trying to face something just so i can get those pretty evenly spaced concentric rings. Could this timer latency be the culprit? Seems strange that it only does it in jog mode. Thanks.

[gar]

060102-1634 EST USA

swarfmacdaddy:

I can not answer your question as I have no experience with TurboCNC.

Your problem should not likely have anything to do with Geckos or the physical machine.

For a software program (TurboCNC) to provide pulses rapidly it has to have fast interrupts (it needs main processor time very often). Your error message is not at all clear to me. That you have a difference in hand vs auto seems to imply a slow timer for the jog function.

Try asking your question in the section on Machine Controllers Software and Solutions, TurboCNC.

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[lakeside]

unless your machine is likw new in the last couple of years I would still think the result of this poll will show a rate of 9600 and 4800 next Fadals that I ran most with the 88 controller all run at 9600 your smaller controller like the AGE 3 by Prototrak run at 4800

[tobyaxis]

Enshu VMC650 Fanuc 11M 9600 Baud Rate.

Used a HAAS with a 3.5 Floppy, what is the Baud Rate on those? Just wondering.

tobyaxis

[gar]

060612-0656 EST USA

tobyaxis:

I believe that Enshu may have an option that you can purchase to upgrade from 9600 to 38,400. If you do mold work and drip feed this could be advantages.

The HAAS 3.5 floppy connects thru a parallel connection and does not use RS232. To compare transfer rates create a valid file about 50,000 bytes. Time the transfer of this file from floppy and thru RS232 at whatever desired baud rate. Then calculate bytes per second for each method.

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[gar]

070615-1656 EST USA

I have combined the results of this poll, as of several days ago, with the similar poll under HAAS. These two graphs are shown together and some comments at my web site
www.beta-a2.com
on the Baud Rate Useage Poll page.

It is surprising there is not more difference.

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[Swag]

unless your machine is likw new in the last couple of years I would still think the result of this poll will show a rate of 9600 and 4800 next Fadals that I ran most with the 88 controller all run at 9600 your smaller controller like the AGE 3 by Prototrak run at 4800

Lakeside
The older Prototrak AGE 3 can be set 2400,4800,9600,11200 if you have the DNC key option by running service code 37 on the machine, I normally run mine at 9600 Buadrate